Just make sure you pick up a roll of dacron or polyester sail repair tape. The nylon rip-stop tape is used on spinnakers. Simply cut off the piece you need, round the corners with scissors so they won't catch on things and peel off(You can shape two identical patches at the same time), remove the paper backing and apply to the sail, both sides. Have the sail on a clean, solid surface and press it on firm so it adheres completely, on small holes like that, they'll last a long time, it is truly a quick fix.

I am wondering what is the cheapest and easyest way to patch small holes in older sail? I have no experience in the area. By small I mean half inch! Help!!!!! Any suggestion welcome

It depends where the hole is located. If the hole is in a low-load area of the sail (like the center of a panel), then repair tape may work.

If the hole is in a highly loaded area of the sail (near any of the corners or along the luff or leach), then sail tape will not work- it needs to be repaired with a sewn patch. In all cases, a sewn patch is really the preferred method.